Fire door



H. A. CHASE June 7, 1966 FIRE DOOR Original Filed June 27, 1963 III! 'IIIIIIIIII I I 1 u INVENTOR HAP/2) A. CHASE 22552 5 7444 a United States Patent f 3,254,592 FIRE DOOR Harry A. Chase, Longview, Wash, assignor to Weyerheauser Company, Tacoma, Wash, a corporation of .Washington Continuation of application Ser. No. 291,162, June 27, 1963. This application May 10, 1965, Ser. No. 458,812 4 Claims. (Cl. 49504.)

This application is a continuation of my prior copending application entitled Fire Door Serial No. 291,162 filed June 27, 1963, now abandoned.

This invention relates to improved building construe tion units and particularly to improved fire doors or the like that are capable of resisting a high temperature fire for at least 90 minutes.

Composite fire doors may at present be manufactured using multiple block calcium silicate-type mineral core with fire retardant treated lumber peripheral bandings. The surfacing, veneers consist of crossbands of wood veneer and a decorative face veneer laminated to the crossband-veneer. Such a door is shown and described in Paul et al., US. Patent No. 2,593,050.

With this type of door, failure occurs at about 60 minutes in the standard fire and hose stream test (ASTM E-119). The mode of failure is often by burning through the peripheral edge bandings which create through openings for the fire to spread to the unexposed surface of the door. With the destruction of the edge bandings on the door during the fire portion of the test, there is provided no bracing against the stop of the door frame, which contributes to the early failure of the door when the standard hose stream is applied.

The standard hose stream test consists of placing a standard nozzle on the end of a fire hose 20 feet away from the door after it has been subjected to a high temperature fire for a predetermined period of time and then blasting the door with a stream of water with a 30 p.s.i. head at the nozzle for a time period depending on the time the door was in the fire. The door must not crumble and fall under this test.

The object of this invention is to provide an improved fire door capable of withstanding a high temperatur fire for at least 90 minutes.

Another object of this invention is to provide an improved fire door having a mineral core which will not crumble and fall when the door receives the impact of a hose stream after a fire.

These and other objects and advantages will become manifestly clear to those skilled in the art when taken in conjunction with the detailed description and drawings, wherein:

FIGURE 1 is a plan view of the improved fire door with portions thereof broken away to show details.

FIGURE 2 is a cross-sectional view taken on line 22 of FIGURE 1.

FIGURE 3 is a cross-sectional view taken on line 33 of FIGURE 1.

FIGURE 4 is a cross-sectional view taken on line 4-4 of FIGURE 1. 7

FIGURE 5 is a cross-sectional view taken on line 55 of FIGURE 1.

FIGURE 6 is a cross-sectional view similar to FIG URE 5 but illustrating a modification ofthe lower cross rails.

Referring now to the drawings, the improved fire door is generally indicated at 1 and comprises a mineral-type core 2 formed of a plurality of blocks 3 and 4. The minoral-type core 2 is of the calcium silicate-type and sold under the trade name of KAYLO by the Owens-Illinois Glass Company.

3,254,592 Patented June 7, 1966 "ice For convenience of manufacture and to control door warpage, a plurality of blocks 3 and 4 are employed with the block 3 extending substantially across the door andthe block 4 extending the rest of the way. The next layer of blocks 3 and 4 are staggered so that the block 3 extends from the opposite direction to provide more stability in the door. Moreover, the blocks 3 and 4 are connected together by a tongue-and-groove structure indicated at 11 and 12 in FIGURE 4. In addition, a tongue-andgroove structure is also provided between all the blocks that contact each other on their edges in a same manner as indicated at 11 and 12 in FIGURE 4.

The outer periphery of the door 1 is provided with a pair of edge stiles 6 and 7 of a particular design, as hereinafter described. Also, a bottom cross rail of two members 5 and 5' is employed that extends between the lower ends of the edge stiles 6 and 7. An upper cross rail 8 is provided which extends between the upper ends of the edge stiles 6 and 7. In practice the lower cross rail members 5 and 5 are glued or otherwise adhered to each other to provide a more stable laminated construction. The lower cross rail 5' is provided with a groove 14 which complements a rib or tongue 12 on the mineral core 2 as shown in FIGURE 5. Also, the edge stile 6 (FIGURE 3) is provided with a groove 13 which is complementary to a rib or tongue 12' to facilitate attachment of the core 2 with the edge stile 6. In this regard it should be pointed out that the edge stile 7 and upper cross stile 8 are also provided with similar tongue-andgroove structures to attach the edge stile 7 and the upper cross stile 8 to the core mineral 2. While it has been described that the groove be provided in the stiles and the tongue in the core, it should be pointed out that this structure can readily be reversed and the grooves be provided in the core and the tongue or rib in the stiles. To the upper and lower surfaces of the core 2 and peripheral edge stiles, upper and lower cross bars is laminated a crossband veneer sheet 9. The crossband veneers are treated with commercial fire retardants (ammonium phosphate, ammonium sulphate, borax, boric acid, etc.) by means of common commercial methods, for example, pressure-vacuum treatments, dippingv and the like. To the upper surfaces of the upper and lower cross veneer sheet 9 is provided a decorative veneer sheet 10 which is laminated to the cross veneer sheet 9.

With the door 1 completely assembled as shown in FIGURE 1, the door 1 can now be placed into a door frame 17 which is mounted in the wall 18 of any building structure. The door frame 17 is provided with the usual edge frame members 19 and a top cross member 20 which is secured to the edge members 19. Also, the door frame is provided with the usual door stop 21 which extends the entire length of the edge frame members 19 and the top cross member 20. As is the usual practice, the width of the door stop 21 is from %"'IO 1".

When the door 1 is placed within the frame 17, the edge stiles 6 and 7 and upper cross rail 8 will bear against the door stop 21. It should be noted, that the door 1 is mounted on hinges, not shown, to facilitate assem bling. With the edge stiles 6 and 7 bearing against the door stop 21, an overlapping relationship 22 is provided. This overlapping relationship of the core 2 with the door stop 21 is absolutely essential to the practice of this invention. Accordingly, the edge stiles 6 and 7 must necessarily be of width that is less than the width of the door step 21. Accordingly, the edge stiles 6 and 7 may have a width range of from to preferably between 7 and Therefore, in the event that the edge stiles 6 and 7 are burntaway, as by a high temperature fire, there is provided a bearing surface on the core .2 that will bear against the door stop 21.

Also, it should be pointed out that the top cross rail 8 is of a width less than the width of the door stop 21 so that an overlap 23 is provided which allows the core 2 to engage the upper cross portion of the door stop 21. If the top cross rail 8 is burnt away as by a high temperature fire, a portion of the core 2 will bear against the door stop 21. The range of width sizes of the top rail 8 may range also from A to The width of the bottom cross rail may range from & to perhaps about 1 /2". It should be pointed out that since there is no door stop portion provided for the bottom cross rail to bear against, the particular width thereof is not critically important and can be of the conventional size.

When the above-described door is subjected to the standard hose test, the door is first subjected to a high temperature fire, the temperature ranging up to about 1700 F., for 90 minutes. During this 90-minute heat temperature test, the exposed veneers 9 and will be completely burnt away as will most of the edge stiles 6 and 7 and top and bottom cross members 5, 5' and 8. Moreover, a portion of the veneers 9 and 10 on the unexposed side may be charred where contact is made with metal which conducts heat from the fire. cold side or unexposed side veneers do not flame or propagate glow because of the crossband treatment. Consequently, any charring is confined to the immediate vic- -inity of the hot metal to wood contact, such as around metal frames for vision panels, escutcheon plates, door frame, etc. At the end of the 90 minutes, a nozzle is connected to a fire hose and water under a 30 p.s.i. head at the nozzle is blasted against the door from the fire exposed side. However, since there is sufficient bearing surface of the core 2 against the door stop 21 on its edge surfaces and top surface, the door will not crumble and fall.

Referring now to FIGURE 6, a modification of the improved fire door is disclosed. vThis embodiment discloses a single bottom cross rail indicated at having a groove 16 therein which receives a rib or tongue 12 formed on the mineral core 2. The function of the door of this modification is-identical with that disclosed in FIGURE 1. While specific details of preferred embodiments have However, thebeen set forth above, it will be apparent that many changes and modifications may be made therein without departing from the spirit of the invention. It will therefore be understood that what has been described herein is intended to be illustrative only and is not intended to limit the scope of the invention.

What is claimed is:

1. In combination: a fire door; a door frame having a doorstop therein having a width of up to 1" supporting said fire door; said door comprising a rigid, fireproof, mineral core; a pair of edge stiles, upper and lower cross rails extending around the periphery of said rigid, fireproof mineral core; said rigid, fireproof mineral core spanning the distance between said edge stiles and between said upper and lower cross rails; said edge stiles, upper and lower cross rails, and rigid, fireproof mineral core being covered by a fireproof veneer panel and a decorative veneer panel; each of said edge stiles having a total thickness up to /8 to provide an overlap between said door stop and said rigid, fireproof mineral core of at least /s" whereby upon destruction of said edge stiles by fire, the rigid, fireproof mineral core of said door will bear against said door stop.

2. The improvement as set forth in claim 1 wherein the width of said upper cross rail is between and /8.

3. The improvement as set forth in claim 1 wherein the edge stiles of said fire door have a width of between & and and said top cross rail has a width of between and 4. The improvement as set forth in claim 1 wherein the width of said edge stiles is between A and /z".

References Cited by the Examiner UNITED STATES PATENTS 2,717,062 9/1955 Dusing et al 20-35 2,797,450 7/1957 Ropella 20-35 2,809,402 10/1957 Southworth 2035 HARRISON R. MOSELEY, Primary Exarniner.

REINALDO P. MACHADO, Examiner.

P. C. KANNAN, Assistant Examiner. 

1. IN COMBINATION: A FIRE DOOR; A DOOR FRAME HAVING A DOORSTOP THEREIN HAVING A WIDTH OF UP TO 1" SUPPORTING SAID FIRE DOOR; SAID DOOR COMPRISING A RIGID, FIREPROOF, MINERAL CORE; A PAIR OF EDGE STILES, UPPER AND LOWER CROSS RAILS EXTENDING AROUND THE PERIPERY OF SAID RIGID, FIREPROOF MINERAL CORE; SAID RIGID, FIREPROOF MINERAL CORE SPANNING THE DISTANCE BETWEEN SAID EDGE STILES AND BETWEEN SAID UPPER AND LOWER CROSS RAILS; SAID EDGE STILES, UPPER AND LOWER CROSS RAILS, AND RIGID, FIREPROOF MINERAL CORE BEING COVERED BY A FIREPROOF VENEER PANEL AND A DECORATIVE VENEER PANEL; EACH OF SAID EDGE STILES HAVING A TOTAL THICKNESS UP TO 5/8" TO PROVIDE AN OVERLAP BETWEEN SAID DOOR STOP AND SAID RIGID, FIREPROOF MINERAL CORE OF AT LEAST 1/8" WHEREBY UPON DESTRUCTUION OF SAID EDGE STILES BY FIRE, THE RIGID, FIREPROOF MINERAL CORE OF SAID DOOR WILL BEAR AGAINST SAID DOOR STOP. 